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I saw this older post when searching for information:
On Feb 16, 5:10 pm, Ingo Weiss <rails-mailing-l...@andreas-s.net>
wrote:
> possible?
I have exactly the same need - a front page that has a bit of text
that changes depending on whether the user is logged in or not.
Everything else could be cached using page cacheing.
Hrm.... I'll take a look at the code... maybe something like
'cache_except' is possible?
Thanks,
Dave
--
http://www.dedasys.com/davidw/

> > I have exactly the same need - a front page that has a bit of text> > that changes depending on whether the user is logged in or not.> > Everything else could be cached using page cacheing.> I had the same issue and settled for two cashed versions of my page, one> for logged in users and one for visitors.> I put the code changes into a plugin you might want to have a look at.>> http://rails.co.za/articles/2007/01/10/cachefilter-update> and then some bug fixes
later...http://rails.co.za/articles/2007/02/07/cachefilter......
Looks like a good way of doing it.
I was thinking about something like this:
1) Create a no_cache method as a helper. The trick is that it outputs
something like <%= blah blah %>
2) Cache the page.
3) Render the cached version, which does the substitution on what
no_cache slipped into the cache.
I don't know whether how efficient that is, since the whole page still
has to be parsed up for erb, when there is only one little chunk of
it. I also don't know if there are any lurking problems...
Thanks,
Dave
--
http://www.dedasys.com/davidw/

> I was thinking about something like this:>> 1) Create a no_cache method as a helper. The trick is that it outputs> something like <%= blah blah %>> 2) Cache the page.> 3) Render the cached version, which does the substitution on what> no_cache slipped into the cache.
Ok, some code that seems to work:
class NoCacheFilter
include ActionController::Caching::Actions
def initialize(*actions, &block)
@actions = actions
end
def before(controller)
return unless @actions.include?(controller.action_name.intern)
controller.instance_variable_set '@dont_interpolate_this', true
action_cache_path = ActionCachePath.new(controller)
if cache = controller.read_fragment(action_cache_path.path)
controller.rendered_action_cache = true
set_content_type!(action_cache_path)
controller.send(:render, :inline => cache)
false
end
end
def after(controller)
return if !@actions.include?(controller.action_name.intern) ||
controller.rendered_action_cache
controller.write_fragment(ActionCachePath.path_for(controller),
controller.response.body)
controller.send(:render, :inline => controller.response.body)
end
private
def set_content_type!(action_cache_path)
if extention = action_cache_path.extension
content_type = Mime::EXTENSION_LOOKUP[extention]
action_cache_path.controller.response.content_type =
content_type.to_s
end
end
end
Combined with this helper:
def no_cache(text)
return eval(text) unless @dont_interpolate_this
return "<%= #{text} %>"
end
Things that could perhaps be improved:
1) I don't like setting the variable in the controller.
2) I don't really like the fact that no_cache takes text as an
argument rather than somehow accomplishing the same thing with a
block, but there's no way to get a block's text out, so a string it
is, as far as I can tell.